Plate type ice maker

ABSTRACT

A plate type ice maker for forming chunks of hard ice in which a member provided with an ice-forming passage having a cutting edge at one end thereof is moved over a plane freezing surface to cause ice crystals scraped from the freezing surface by the cutting edge to be forced into the forming passage in which they are subjected to compressive forces sufficient to form a rod of hard ice which emerges from the other end of the passage and which engages a breaker surface which fractures the rod to form a hard piece of ice.

BACKGROUND OF THE INVENTION

There are known in the prior art two general types of ice makers. Thefirst of these which produces what is known in the art as flake or chipice rather than hard ice includes an auger or the like which scrapes icecrystals from a tubular freezing surface and feeds the resultant slushice outwardly through a die or the like to form flake or chip ice.Alternatively, a cylindrical freezing chamber can be employed andscraper blades on the outside of the chamber remove the ice crystals. Inall ice makers of this type this chamber is vertical and of tubular orcylindrical shape. While ice makers of this type produce ice on acontinuous basis, they embody the defect that the tubular evaporatorconfiguration is mechanically weak and it requires various bearings andwater seals. It is relatively costly to produce. In addition, thequality of ice produced on ice makers of this type is not consistent butis a function of the ambient temperature and the temperature of theincoming water and of the condition of the refrigerating equipment.

The other type ice maker known in the art is a "cube" ice maker in whichwater in a container is subjected to the action of a refrigerant. Whilesome of the cube ice makers employ flat plate type evaporators, none ofthem produce ice on a continuous basis. That is to say, the freezingcycle is carried on until ice of the thickness of about one quarter toone half inch is formed and is then interrupted. Following interruptionof the freezing cycle a harvest or defrost cycle is started. Thus, icemakers of this type do not produce ice on a continuous basis. While theice is of high quality, the machine is extremely inefficient owing tothe inherent insulating property of the ice itself. Stated otherwise, arelatively great refrigerating effort is required to produce ice of anyappreciable thickness.

We have invented a plate type ice maker which overcomes the defects ofice makers of the prior art. Our plate type ice maker is adapted toproduce chunks of hard ice on a continuous basis. It is more rugged thanare auger type ice makers of the prior art. It is less expensive tomanufacture than auger type ice makers. It is more efficient than arecube type ice makers of the prior art. It does not require the alternatefreeze and harvest cycles of cube type ice makers of the prior art.

SUMMARY OF THE INVENTION

One object of our invention is to provide a plate type ice maker whichovercomes the defects of ice makers of the prior art.

Another object of our invention is to provide a plate type ice makerwhich produces chunks of hard ice on a continuous basis.

A further object of our invention is to provide a plate type ice makerwhich is more rugged than are auger type ice makers of the prior art.

A still further object of our invention is to provide a plate type icemaker which is less expensive to produce than are auger type ice makersof the prior art.

Yet another object of our invention is to provide a plate type ice makerwhich is more efficient than are cube type ice makers of the prior art.

Yet another object of our invention is to provide a plate type ice makerfor producing pieces of hard ice without the necessity for alternatefreeze and harvest cycles.

Other and further objects of our invention will appear from thefollowing description.

In general, our invention contemplates the provision of a plate type icemaker in which a cutting edge at the entrance to an ice-forming passagemoves over a plane freezing surface to scrape crystals of ice from thesurface and force them into the ice forming passage in which the slushice is compressed to such a degree as to form a hard rod of ice whichemerges from the passage and impinges on a breaker surface whichfractures the rod thus to form pieces of hard ice.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form part of the instantspecification and which are to be read in conjunction therewith and inwhich like reference numerals are used to indicate like parts in thevarious views:

FIG. 1 is a top plan view of one form of our plate type ice maker withparts removed and with other parts broken away.

FIG. 2 is a sectional view of the form of our plate type ice maker shownin FIG. 1 taken along the line 2--2 of FIG. 1.

FIG. 3 is a sectional view of one of the ice rod forming units of theform of our plate type ice maker illustrated in FIGS. 1 and 2.

FIG. 4 is a fragmentary top plan view of an alternate embodiment of ourplate type ice maker with parts removed.

FIG. 5 is a sectional view of the embodiment of our ice makerillustrated in FIG. 4.

FIG. 6 is a section view taken along a diametral chord of the form ofour ice maker shown in FIGS. 4 and 5 to illustrate the mode of operationthereof.

FIG. 7 is a fragmentary sectional view of a further form of our platetype ice maker.

FIG. 8 is a fragmentary sectional view of the form of our plate type icemaker shown in FIG. 7 and taken along the path of movement of a cutterthereof to illustrate the operations thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 to 3, one form of our plate type ice makerindicated generally by the reference character 10, includes a motor 12,which provides the input to a gear box 14 having an output shaft 16. Abracket 18 secured to a boss 20 on the gear box 14 is attached by meansof a screw 22 or the like to an evaporator plate 24. We form the uppersurface of the evaporator plate 24 with a plurality of coil-formingchannels 26. Refrigerant may be introduced into the channels 26 throughan inlet 28. A return outlet 30 permits the refrigerant to pass back tothe compressor (not shown).

Shaft 16 extends upwardly through a hollow hub 32 on the evaporatorplate 24. The arrangement is such that shaft 16 can rotate in the hub32. An annular freezer plate 34 is secured over the channels 26 by anysuitable means known to the art. Refrigerant flowing through thechannels 26 cools the plate 34 to permit ice crystals to form thereon ina manner to be described.

The form of our ice maker 10 shown in FIGS. 1 to 3 includes three cubeor ice piece-forming units indicated generally respectively by thereference characters 36, 38 and 40. Since all of the units 36, 38 and 40are substantially identical we will describe only the unit 36 in detail.The unit 36 includes a chute-forming member 42 provided with an icechute 44 which, together with a roof or top member 46, forms a channelfor the reception of slush ice. The roof member may be secured to thechannel-forming member 42 in any suitable manner. It includes aresilient tip portion 48 adapted to move to the broken line positionillustrated in FIG. 3 in response to movement of a rod of ice up thepassage. The member 42 further is formed with a scraper edge 50 adaptedto scrape ice crystals from the surface of the plate 34. The leadingedge of a rod of ice emerging from chute 44 passes under the tip 48,forcing it to the broken line position and ultimately engages a breakersurface 52 located in a plane forming an angle of less than 90° with theplane of the chute base and a piece of ice breaks off the rod. Thelength L of the piece is approximately equal to the distance betweensurface 52 and the end of tip 48, as indicated in FIG. 3.

Member 42 is formed with a peripheral flange 54 adapted to receivescrews 56 to secure the member 42 in an opening 58 in a support plate 60threaded onto shaft 16 for rotation therewith. We provide the plate 60with a number of reinforcing ribs 62.

It is to be noted that the respective units 36, 38 and 40 are radiallystaggered as indicated in FIG. 1. That is, unit 36 is radiallypositioned so that its edge 50 rides over the outermost portion of thesurface of the plate 34. Unit 38 is so positioned that its edge 50 ridesover the central portion of the annular plate 34. Unit 40 is furthestinboard so that its edge 50 rides over the innermost portion of theplate 34. If desired, we may provide some overlap between the edges 50of the various units. We provide the surface of the plate 34 with spacedradially extending grooves 64 for preventing a body of ice from movingalong with the rotating support plate 60 when shaft 16 is driven.

We mount a cover plate 66 on the plate 60 for rotation therewith. Aschunks of ice are formed in the various units in a manner to bedescribed they are discharged at locations above the plate 66 so as tobe retained thereon. Any water running off the formed ice passesdownwardly over the edge of the plate 66. We mount a surrounding wall 68on the outer edge of plate 24 to provide a storage space for formed ice.The entire assembly is provided with an insulating jacket 72. An inletpipe 70 permits water to be introduced into the space over the freezerplate 34. Preferably, we maintain the water at a level indicated by thedot-dash line in FIG. 2. A cover 74 is adapted to be removably securedover the top of the wall 68 by any suitable means such for example as byscrews 76.

Referring now to FIGS. 4 to 6, an alternate embodiment of our plate typeice maker indicated generally by the reference character 78 includes anevaporator plate 80 covered with a plate 82 providing the freezingsurface. The output shaft 84 of a gear box or the like passes upwardlythrough the central hollow hub of the plate 80 and is secured to anextruding head support 86 by means of a key 90 or the like the ends ofwhich engage recesses in the hub 88 of the support plate 86. A nut 92threaded onto shaft 84 is adapted to position the support 86 on theshaft.

The support 86 carries a scraper blade 94 adapted to move over thesurface 82 when the support member 86 is driven by shaft 84. It will beappreciated that the blade 94 may include more than one scraping edge,such for example as a second edge at a location circumferentially spacedaround hub 88 from the edge shown in the drawings.

We mount a respective extruder ad 96 over each of the scraping edges ofthe blade 94. The member 86 includes downwardly extending partitions 98which, together with the upper surface of the scraping blade 94 provideextruding passages for the formation of ice. It will be seen that thespace between the outer wall portion of support 86 and the hub 88 andbetween the top of head 96 and the cutting edge of blade 94 forms aplenum chamber just ahead of passages 100 in the direction of movementof the head 96. Ice being scraped from plate 82 collects in the plenumchamber and is partially dewatered in the course of its passagetherethrough. Finally it is forced into passages 100 wherein it is.[.extended.]. .Iadd.extruded .Iaddend.to to form hard ice.

Each of the passages 100 has an outlet 104 leading into a recess formedin the top of a drip ring 106 secured to shaft 84 for rotationtherewith. Each recess 108 is provided with a surface 110 on which a rodof ice emerging from the outlet 104 impinges. In FIG. 6 we haveindicated water by the reference character 112, the thin film of ice onthe surface of plate 82 by 114, slush ice in the plenum chamber by thereference character 116, the rod of ice by 118, and a broken off icepiece by 120.

Referring now to FIGS. 7 and 8, we have illustrated yet another form ofour plate type ice maker, indicated generally by the reference character122. The ice maker 122 includes a gear motor 124 having an output shaft126. A stationary housing 128 formed with a base 130 is secured to thegear motor housing by any suitable means such, for example, as by screws132. A refrigerant coil-forming member 134 supported on the base 130carries a freezer plate 136 on the surface of which ice crystals formwhen water is supplied to the plate and when refrigerant flows in thecoil-forming assembly 134.

The ice maker 122 includes a cutter disc 138 formed with a hub 140 whichis screwed onto or otherwise secured to the shaft 126 for rotationtherewith. We provide a cover plate 142 secured to hub 140 in anysuitable manner so as to be driven together with the cutter disc 138.

The salient feature of the form of our plate type ice maker illustratedin FIGS. 7 and 8 is a plurality of circumferentially extending radiallyspaced ribs or walls 144, 146, 148 and 150 on the bottom of the cutterplate 138. Pairs of adjacent ribs 144 and 146, 146 and 148, and 148 and150 provide confined passages 152, 154 and 156 for ice removed from thesurface of plate 136 in a manner to be described.

Our ice maker 122 includes a plurality of ice rod-forming assembliesindicated generally by the reference character 158. While we haveillustrated only one assembly 158 in FIGS. 7 and 8, it will readily beappreciated from the description hereinbelow that we provide three suchassemblies, one for each of the channels 152, 154 and 156. Each of thesechannels is provided with a respective opening 160 surrounded by a boss162 for receiving an assembly 158. Each assembly 158 is formed with aninclined passage 164 and with a base 166 secured to a boss 162 by anysuitable means such, for example, as by screws 168. An extension 170 onthe trailing wall of the inclined passage 164 extends downwardly throughthe opening 160 and to a location at which a scraper edge 172 thereoncooperates with the portion of the freezer plate 136 associated with thechannel 154 for example.

Each assembly 158 includes a spring finger 174 analogous to the finger46 of the form of our invention illustrated in FIGS. 1 to 3. In the formof our ice cube maker illustrated in FIGS. 7 and 8 however, the fingers174 are provided with pivotal supports 176 which mount the fingers onthe assemblies 158. As ice is scraped off the surface of the plate 136by the scraper edge 172, it builds up in the channel 154 and forces itsway up the inclined passage 164 so as ultimately to engage the finger174. Upon continued rotation of the scraper plate 138, the action of thefinger 174 compresses the slush ice until ultimately a rod of iceemerges from the upper end of the inclined passage 164.

We form the cover 142 with a respective prominence or boss 178 over eachof the assemblies 158. The underside of the top of each boss 178provides a breaker surface 180. As the rod moves upwardly out of thepassage 164 its upper edge engages the surface 180 so that a cube of iceis broken off the upper end of the rod. It will readily be appreciatedthat the length of the cube or piece of ice broken off is determined bythe distance between the upper end of the trailing edge of the passage164 and the surface 180. Pieces of ice thus broken off the upper end ofthe rod outwardly of the cover 142 through openings 182 in the bosses.This ice accumulates within the housing 128 over the cover 142. It willbe seen that any melt-down from the accumulated ice flows downwardlyover the edges of the cover and back toward the freezer plate 136.

In operation of the form of our invention illustrated in FIGS. 1 to 3,water is introduced into the space over the surface of plate 34 throughline 70. A thin film of ice forms on top of the plate 34. As shaft 16rotates, the respective scraper or cutter edges 50 of the units 36, 38and 40 traverse different portions of the upper surface of the plate 34and scrape or cut ice from the film of ice as slush ice. The radialgrooves 64 prevent any body of ice being moved along with the rotatingunits 36, 38 and 40. It will be appreciated that as a cutting edge 50removes ice from the film formed on the surface of plate 34, a diametraltrack in line with the cutter is formed in the film of ice. Thus, thecut ice is contained within this track and is immediately forced up theinclined plane formed by the bottom of chute 44. Owing to the fact thatsuch a diametral track is formed, all ice is ultimately forced up thechute. In this manner, the slush ice is raised above the water levelmaintained in the freezing chamber. As more ice is forced up the chute,water is removed therefrom by elevating it above the water level.Ultimately the ice is forced against the spring tip 48 of the roof ortop 46 of the chute 44. The pressure exerted by this closure forcesadditional water out of the ice until sufficient force is exerted by therod of ice on the tip 48 to force it to the broken line position shownin FIG. 3. By this time, the ice emerging from the top of the chute ishard bar ice. Finally this bar of ice impinges on the surface 52 whichis at an angle of less than 90° to the bottom of the chute. Owing to thefact that the ice is brittle, it will fracture at the end of the tip 48in its broken line position to form a chunk of ice. The thus formedchunks of ice collect on top of the cover 66 so as to provide a supplyof hard chunks of ice.

It is to be noted that in the form of our invention shown in FIGS. 1 to3 radial and thrust loads of the cutters are applied directly to thebearings of the gear motor output shaft. Moreover, since the threecutter edges are displaced from one another by 120° the leads and forcesdeveloped by the edges are relatively evenly distributed. The evaporatorplate is mounted on the output shaft 16 so as to eliminate thepossibility of misalignment between the freezing surface and the cuttingedges 50. Our arrangement eliminates the necessity for providing waterseals and shaft bearings such as cause problems with auger type icemakers of the prior art.

In operation of the form of our ice maker shown in FIGS. 4 to 6, thecutting edges of the blade 94 scrape slush ice off the film of ice 114formed on the upper surface of plate 82 from the water 112. This slushice is forced into the plenum chamber leading into the passages 100, inthe course of movement through which it is extruded into the hard rod118. Ultimately the leading edge of the rod strikes surface 110 to breakthe rod into chunks of ice. The amount of compression exerted on theslush ice is determined not by the lead of an auger, as in auger typeice makers of the prior art, but rather by the quantity of ice collectedin the plenum chamber. The quantity of ice thus collected is dependentupon the velocity of the cutter and the refrigeration conditions of thefreezing surface. The quality of the extruded ice does not change. Itrequires only more or less revolutions of the device to produce ice of agiven length and size.

In operation of the form of our invention illustrated in FIGS. 7 and 8,the scraper edges 172 of the respective units 158 scrape ice crystalsoff the surface of plate 136. In this form of our invention, the wallsor ribs 144, 146, 148 and 150 form confined channels extendingcircumferentially of the plate 136 and in line with the cutting edges172 and the entries of the inclined passages 164 of the units 158. Thesepassages ensure that ice scraped from the surface of plate 136 willenter the passages 164. As this ice is formed upwardly along theinclined passages 164, a rod of hard ice is formed in a manner similarto that in the operation of the form of our invention illustrated inFIGS. 1 to 3. As a rod of ice emerges from the top of the inclinedpassage 164, it strikes the breaker surface 180 so that pieces of hardice break off and are discharged outwardly through outlets 182 to thestorage area in housing 128 above the cover 142.

It will be seen that we have accomplished the objects of our invention.We have provided a plate type ice maker which overcomes the defects ofice makers of the prior art. Our ice maker is adapted to make hardchunks of ice on a continuous basis. It does not require alternatefreezing and harvest cycles. It is more efficient than are cube type icemakers of the prior art. It is more rugged and is less expensive toconstruct than are auger type ice makers of the prior art.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of ourclaims. It is further obvious that various changes may be made indetails within the scope of our claims without departing from the spiritof our invention. It is, therefore, to be understood that our inventionis not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:
 1. Apparatus forforming hard pieces of ice including in combination, means forming anextended freezing surface, means forming an extruding passage having anentry and an exit .Iadd.and a bottom extending upwardly and away fromsaid surface.Iaddend., a gathering edge .Iadd.provided on said passageforming means for movement therewith .Iaddend.adjacent to said entry,and means mounting said passage forming means for movement relative tosaid surface with said gathering edge adjacent to said surface to removeice crystals from a film of ice on said surface and to deliver said icecrystals to said entry in the form of slush ice.Iadd., said passageforming means being provided with means for exerting a compressive forceon slush ice delivered thereto so that slush ice .Iaddend.which enterssaid passage .[.and.]. emerges from said exit in the form of a hard rodof ice in response to relative movement between said passage formingmeans and said surface.
 2. Apparatus as in claim 1 in which said surfaceis generally horizontal and in which said passage forming means ismounted above said surface.
 3. Apparatus as in claim 2 including meansfor supplying water to a predetermined level over said surface and inwhich said passage exit is above said level.
 4. Apparatus as in claim 3in which said passage forms an inclined plane with reference to saidsurface from said entry to said exit.
 5. Apparatus as in claim 4including means for breaking said rod emerging from said exit. 6.Apparatus as in claim 5 .[.including.]. .Iadd.in which said compressiveforce exerting means includes .Iaddend. means forming a plenum chamberbetween said gathering edge and said entry.
 7. Apparatus as in claim 5.[.including.]. .Iadd.in which said compressive force exerting meansincludes .Iaddend. resilient means normally closing said exit, saidresilient means adapted to be actuated by the ice emerging from saidpassage.
 8. Apparatus as in claim 5 in which said breaker meanscomprises a surface making an angle of less than 90° with said inclinedplane.
 9. Apparatus for forming hard pieces of ice including incombination, means providing an extended ice forming surface, meansforming an extrusion passage having an entry and an exit .Iadd.and abottom extending upwardly and away from said surface.Iaddend., saidpassage forming means being provided with a gathering edge adjacent tosaid entry, means mounting said surface forming means and said passageforming means for relative rotary movement with said passage above saidsurface and with said gathering edge adjacent to said surface and withsaid exit above said entry, and means for driving said passage formingmeans and said surface forming means relative to each other to causesaid gathering edge to remove ice from said ice-forming surface and tofeed slush ice into said passage.Iadd., said passage forming means beingprovided with means for exerting a compressive force on slush ice fedthereto .Iaddend.to form a mass of hard ice emerging from said exit. 10.Apparatus as in claim 9 including means for breaking said mass of iceemerging from said exit.
 11. Apparatus as in claim 10 in which saidbreaking means comprises a surface disposed at an angle to the directionof movement of said mass.
 12. Apparatus as in claim 11 .[.including.]..Iadd.in which said compressive force exerting means include.Iaddend.resilient means normally closing said exit. .[., said resilientmeans exerting a compressive force on ice moving into said passage underthe influence of said relative movement.].
 13. Apparatus as in claim 9.[.including.]. .Iadd.in which said compressive force exerting meansincludes .Iaddend.resilient means normally closing said exit .[., saidresilient means exerting a compressive force on ice moving into saidpassage under the influence of said relative movement.]., said resilientmeans being actuated to open said exit in response to movement of a massof hard ice toward said exit.
 14. Apparatus as in claim 13 in which saidresilient means is a leaf spring forming part of the wall of saidpassage.
 15. Apparatus as in claim 14 including means forming a breakersurface making an angle with the direction of movement of said rod, saidsurface being spaced from said exit.
 16. Apparatus as in claim 9 inwhich sad passage forming means forms a plurality of radially spacedpassages.
 17. Apparatus as in claim 16 in which said .[.passage formingmeans provide.]. .Iadd.compressive force exerting means comprises.Iaddend.a common plenum chamber .Iadd.formed by said passage formingmeans .Iaddend.between said gathering edge and the passage entries. 18.Apparatus as in claim 9 including a plurality of passage forming means,said passage forming means being radially and circumferentially spacedwith reference to the axis of rotary movement thereof.
 19. Apparatus forforming hard pieces of ice including in combination means providing agenerally horizontally disposed annular extended ice forming surface, aplurality of hard ice forming units, each of said hard ice forming unitshaving an inclined extruding passage therein extending from an entry toan exit, each of said units having a cutting edge adjacent to saidentry, each of said units having resilient means normally closing saidexit and having an ice breaker surface spaced from said exit and makingan acute angle with the direction of inclination of said passage, meansmounting said units at respective locations circumferentially spaced andradially spaced with respect to the center of said annulus for relativerotary movement of said units and said surface providing means aroundsaid center and with said cutting edges closely adjacent to said surfaceand means for driving said surface providing means and said mountingmeans relative to each other to cause said cutting edges to remove saidice from said surface and to feed slush ice into said passage entries tocause rods of ice to form in said passages and to cause said rods toactuate said resilient means to open said passage exit and to impinge onsaid breaker surfaces to provide said pieces of hard clear ice. 20.Apparatus as in claim 19 including means for supplying water to apredetermined level over said surface, said exits being positioned abovesaid level.
 21. Apparatus as in claim 9 in which said mounting meanscomprises means forming an elongated ice confining channel above andextending generally parallel to said ice forming surface, said passageopening into said channel.
 22. Apparatus as in claim 19 in which saidunit mounting means comprises means forming a plurality of radiallyspaced circumferentially extending channels over said ice formingsurface, said extruding passage extending into respective channels.